Load lifter



June 25, 1946. w. A. ROSS 2,402,579

LOAD .LIFTER Filed May 24, 1945 5 Sheets-Sheet l 7 June 25, 1946. w. A.Ross 2,402,579

LOAD LIFTER Filed May 24, 1945 -3 Sheets-Sheet 2 IN VEN TOR.

Patented June 25, 1946 UNITED STATES PATENT OFFICE LOAD LIFTER WilliamA. Boss, Springfield, Ill., assignor to Weaver Manufacturing Company,Springfield, 111., a corporation of Illinois Application May 24, 1945,Serial No. 595,505

2 Claims. 1

Substantial advancement in the structural and functional properties ofload elevating and loading appliances constitute the subject matter ofthe present invention whereby to afiord mechanisms of this generalcharacter with constructional features which permit the devices tooperate to substantially better advantage than heretofore.

Among the various aims of the invention may be mentioned the provisionof an apparatus of this type which avoids complexity of construction,which may be manufactured at comparatively small cost, and whichfunctions advantagously and efliciently.

To enable those skilled in this art to understand the invention and theadvantages which accrue from its employment a present preferredembodiment of the invention has been illustrated in the accompanyingdrawings forming a part of this specification and to which referenceshould be had in connection with the following detailed description,and, for simplicity, like reference characters have been employed todesignate the same parts throughout the several views of the drawings.

In the drawings:

Figure 1 shows the appliance in elevated relation in perspective;

Figure 2 portrays the apparatus in perspective in its lowered condition;

Figure 3 is a side elevation of the mechanism in partially raisedcondition;

Figure 4 is a similar view of the structure in further depressedrelation;

Figure 5 is a plan of the construction with its supporting carriage orsaddle, denoted as a whole by the reference numeral l5, and which may beof any suitable size, shape and form, depending upon the type of load tobe elevated, includes twin, transversely-registered, pantograph-linkageseach having, in the present instance, three pairs of channel-bar linksl6, l6, l1, l1 and l8, [8, each hinged at its middle at l8 to the centerof its companion link of the pair and also hinged 2 to ends of otherlinks at 2|, all in the well known pantograph arrangement.

One I it of each pair of upper links at its top is hinged at a fixedpoint 22 to the corresponding side of the forward portion of carriageIS, the upper end of its companion link 18 being hinged at 23 to a frame24 slidable lengthwise in the sides of the longitudinal channel-barsconstituting parts of the carriage I 5, whereby such end of each of thespecified top links H8, H8 may travel lengthwise of the carriage duringits up and down movements.

The lower end of each of the two links it is hinged at 25 to thecorresponding chassis, side channel-bar and the lowermost end of each ofthe companion links I I6 is provided with a roller at 26 adapted totravel forwardly and rearwardly in a channel guide-bar 21 fixed to theouter face of the answering side-bar of the chassisframe.

To actuate these two, complementary, transversely-registeredpantograph-linkages simultaneously, the following means is provided.

An oil-pump 28, operated by rocking handle l4, feeds oil under pressureinto a horizontal cylinder 29 hinged on the chassis at 30, thepiston-rod 3| of the piston (not shown) in the cylinder being rockinglyconnected at 32 to the short arm of a bell-crank 33 fulcrumed at 34 on astationary bracliet 35 mounted on the chassis. the longer arm of thebell-crank being joined by a short link 36 to the pivotal connectionsIS. IS of the two pairs of links l6 and I It as by a crossrod or shaftI31 at that point.

Obviously, as the oil under pressure enters cylinder 29, its piston-rod3| rocks the bellcrank 33 around its fixed axis 34, thus swinging thelonger arm of the bell-crank up and forcing both pantograph-linkages andtheir common carriage up by the force applied through the connectinglink 36.

It will be clear that when the operative parts are collapsed, asportrayed in Figure 7, the cylinder and its piston-rod are not in suchposition to apply its power to best advantage and it is thereforedesirable to employ a booster means to assist such main operatingmechanism during the first or initial portion of its action, that is tosay, until its parts have changed their .position to render them moreefflcient and effective.

Accordingly, the following additional or supplemental power-operatingmedium is employed during the introductory or inaugural action of themain power means.

As presented, perhaps most clearly in Figure 6, a smaller auxiliary orbooster cylinder 21 is hinged or pivoted at 38 on the long arm of thebell-crank, the turning of such cylinder about the axis 38 being limitedor restricted by the adjacent mechanical parts, the piston-rod 39 of thepiston in the cylinder having a rounded head or end 41 adapted to coactwith a complementary, concave, .socket member 42 welded or otherwisefixedly secured to the two links l8, l8 and adapted to rest on the head4| during the first portion of the upward action.

The lower portion of the interior of the smaller cylinder 31 isconnected by a flexible conduit 43 joined to the interior of cylinder 29so that the oil under pressure operates the pistons in both cylinders atthe same time.

Assuming that the appliance is in the completely folded, lowermostcondition, as depicted in Figure 2, and that it is desired to raise aload resting in the seat or carriage IS, the operator by manuallyrocking or oscillating handle [4 simultaneously pumps oil under pressureinto the main and booster cylinders 29 and 31, respectively, therebyinitiating the elevation of the carriage and its load through thepiston-rod 3|, bell-crank 33, link 36 and the pair ofpantograph-linkages, this action being aided and facilitated by theupward pressure ofpiston-rod 39 acting on the same linkages through thecoacting part .39 and 42, the cylinder, piston and pistonrod rockingsomewhatas they ascend by the conjoint-action of .part 42 with the endof the piston-rod.

By the time the main operating means reaches a condition and position ofcooperating elements to more eillciently and forcefully perform itslifting action, the link l8 will have risen sufllciently to raise thecap 42 away from the piston-rod l9 and the latter will remain inactivebecause it has reached its limit of extension.

when the carriage is to descend the usual 11:-

lease-valve (not shown) of the pump discharges the machine is equippedwith a pair of outrlgsers 5|, 5| hinged to the opposite sides of thechassis extended, active positions or folded back against the chassis ininoperative positions.

The arms of these Outriggers have adjustable Jack-screws SI, 53 at theirfree ends with groundengaging discs or feet 54, 54.

Manifestly, by turning the jack-screw cranks 55, 55 and thereby settingthe height of these arms the appliance may be stabilized or it may betilted, if desired, to either side if necessary when in raised position.

As the appliance has been used as a bomb loading truck mounted onpneumatictires, the out-. riggers prevent swaying and allow lateral motion, as referred to.

The appliance, as described above, is not nec-. essarily limited andrestricted to the precis features of structure since these may bemodified within reasonable limits without digression from the nature andprinciple of the invention, as de fined in the appended claims, andwithout loss ofl any of the material benefits or advantages accruingfrom the employment of the invention in physical form.

I claim:

1. In a load-lifting apparatus including a base,

a load-lifting carriage, a pair of transverselyregisteredcarriage-operating pantograph-linkages between said base and carriageand means to actuate said linkages simultaneously, the novel improvementof said actuating-means including a bell-crank hinged on said base, mainhydraulic operating-means connected to the shorter arm of thebell-crank, a link connecting the longer arm of said bell-crank t0 thelower pairs of links of the two linkages, and a booster hydraulic meansmounted on the longer arm of said bell-crank and adapted to cooperatewith said linkages to assist in raising them dining the initial portiononly of the lifting operation of said main hydraulic means.

2. The novel improvement set forth in claim 1, I including theadditional novel improvement that said booster hydraulic means is hingedon the longer arm of said bell-crank and said linkages have meanscooperating with said booster hydraulic means and rocking the latterdining at least a portion of the active operation thereof.

wnnaua. Ross.

